U.S. patent number 5,626,562 [Application Number 08/345,104] was granted by the patent office on 1997-05-06 for drug delivery catheter.
This patent grant is currently assigned to Devices for Vascular Intervention. Invention is credited to Anthony J. Castro.
United States Patent |
5,626,562 |
Castro |
May 6, 1997 |
Drug delivery catheter
Abstract
A device and method for the localized treatment of vasculature
with drugs and medicaments is described herein. Centrifugal force
is used to drive a material from a reservoir to the outer surface
of the application device and thereby deliver the treatment
substance to the chosen area.
Inventors: |
Castro; Anthony J. (San
Francisco, CA) |
Assignee: |
Devices for Vascular
Intervention (Santa Clara, CA)
|
Family
ID: |
23353544 |
Appl.
No.: |
08/345,104 |
Filed: |
November 28, 1994 |
Current U.S.
Class: |
604/508; 606/159;
606/180 |
Current CPC
Class: |
A61B
17/22 (20130101); A61M 25/00 (20130101); A61B
2017/22084 (20130101); A61M 31/00 (20130101) |
Current International
Class: |
A61B
17/22 (20060101); A61M 25/00 (20060101); A61M
31/00 (20060101); A61M 031/00 () |
Field of
Search: |
;604/51-55,22,96,891.1
;606/159,170,171,180 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Yasko; John D.
Attorney, Agent or Firm: Castro, Esq.; Anthony J. Chaikin,
Esq.; Douglas A. Peninsula IP Group
Claims
What is claimed is:
1. A device for the application of medicaments to a biological
conduit, comprising:
a rotatable and axially translatable applicator, the applicator
including:
an outer surface;
a distal end and a proximal end;
an interior reservoir for containing a medicament;
at least one delivery path connecting the interior reservoir to the
surface of the applicator; and
a drive cable attached to the proximal end of said applicator for
imparting and translational motion to the applicator,
whereby the medicament contained in the reservoir is deliverable to
the biological conduit when the applicator is rotated.
2. The device of claim 1 wherein the biological conduit is a blood
vessel.
3. The device of claim 2 wherein the blood vessel is a coronary
blood vessel.
4. The device of claim 1 wherein the delivery path is of capillary
dimensions.
5. The device of claim 4 wherein the biological conduit is a blood
vessel.
6. The device of claim 5 wherein the blood vessel is a coronary
blood vessel.
7. A device for the removal of tissue from, and the application of
medicaments to, a biological conduit, comprising:
a rotatable and axially translatable applicator, the applicator
including:
an outer surface;
a distal end and a proximal end;
an interior reservoir for containing a medicament;
at least one delivery path connecting the interior reservoir to the
surface of the applicator; and
a drive cable attached to the proximal end of said applicator for
imparting rotational and translational motion to the
applicator,
whereby the medicament contained in the reservoir is deliverable to
the biological conduit when the applicator is rotated.
8. The device of claim 7 wherein the biological conduit is a blood
vessel.
9. The device of claim 8 wherein the blood vessel is a coronary
blood vessel.
10. The device of claim 7 wherein the delivery path is of capillary
dimensions.
11. The device of claim 10 wherein the biological conduit is a
blood vessel.
12. The device of claim 11 wherein the blood vessel is a coronary
blood vessel.
13. A method for localized application of medicaments within a
biological conduit, the method comprising the steps of:
providing a device that includes:
a rotatable and axially translatable applicator, the applicator
including
an outer surface;
a proximal end;
a distal end;
an interior medicament containing reservoir;
at least one delivery path connecting the interior medicament
reservoir to the surface of the applicator; and
a drive cable attached to the proximal end of said applicator for
imparting rotational motion to said applicator,
inserting the device in the biological conduit so that the
applicator is adjacent to the treatment area; and
rotating the applicator at a speed sufficient to force the
contained medicament to the surface of the applicator and onto the
surface of the biological conduit,
whereby the medicament contained in the reservoir is delivered to
the biological conduit.
14. The method of claim 13 wherein the biological conduit is a
blood vessel.
15. The method of claim 14 wherein the blood vessel is a coronary
blood vessel.
16. The method of claim 13 wherein the delivery path is of
capillary dimensions.
17. The method of claim 16 where the biological conduit is a blood
vessel.
18. The method of claim 17 where the blood vessel is a coronary
blood vessel.
19. A method for surgically intervening within a biological
conduit, the method comprising the steps of:
providing a device that includes:
a rotatable and axially translatable applicator, the applicator
including
an outer surface;
a proximal end;
a distal end;
a cutting means at the distal end of the applicator;
an interior medicament containing reservoir;
at least one delivery path connecting the interior medicament
reservoir to the surface of the applicator; and
a drive cable attached to the proximal end of said applicator for
imparting rotational and translational motion to said
applicator,
inserting the device in the biological conduit so that the
applicator is adjacent to the treatment area; and rotating the
applicator at a speed sufficient to force the contained medicament
to the surface of the applicator and onto the surface of the
biological conduit,
whereby the medicament contained in the reservoir is delivered to
the biological conduit.
20. The method of claim 19 wherein the biological conduit is a
blood vessel.
21. The method of claim 20 wherein the blood vessel is a coronary
blood vessel.
22. The method of claim 19 wherein the delivery path is of
capillary dimensions.
23. The method of claim 22 wherein the delivery path is of
capillary dimensions.
24. The method of claim 23 wherein the blood vessel is a coronary
blood vessel.
Description
RELATED APPLICATIONS
This application incorporates by reference U.S. patent application
Ser. No. 08/149,587, filed Nov. 11, 1993, entitled "Improved Cutter
Device," and Ser. No. {08/597,603,}filed Feb. 6, 1996, entitled
"Composite Cutter."
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a device and method for the treatment of
specific areas of inner surfaces of biological conduits with
medicaments.
2. Previous Art
Atherosclerosis is a progressive disease wherein fatty, fibrous,
calcific, or thrombotic deposits produce atheromatous plaques
within and beneath the intima which is the innermost layer of
arteries. The most commonly affected vessels are the aorta, iliac,
femoral, coronary and cerebral arteries. Untreated coronary artery
disease can lead to angina, hypertension, myocardial infection,
strokes and the like. Atherosclerotic blockages can occur anywhere
within the thicket of vessels and arteries that service the heart.
Regions of blood vessels that are blocked by atheroma (plaque) or
other materials are generally referred to herein as stenotic
regions, and the blocking material as stenotic material. The
composition of the stenotic material can vary from hard
calcium-containing lesions to fatty lipid-based coatings on the
inside of the coronary arteries. Stenotic materials deposited on
blood vessel walls are often relatively soft and tractable.
However, in many cases, the stenotic material may contain a
significant amount of calcified and hardened material. A number of
methods such as coronary artery bypass graft (CABG) surgery,
percutaneous transluminal coronary angioplasty, (PCTA), direction
coronary atherectomy (DCA), energetic ablation, and stenting, are
used in attempts to restore the narrowed blood vessels to, as close
as is possible, to their original diameters. In percutaneous
transluminal coronary angioplasty, sometimes called balloon
angioplasty, during coronary catheterization, an inflatable balloon
is inserted in a coronary artery in the region of coronary
stenosis. Inflation of the balloon for 15-30 seconds results in an
expansion of the narrowed lumen or passageway. Devices suitable for
PCTA have been described is U.S. patents such as U.S. Pat. No.
4,323,071. Directional Coronary Atherectomy is a procedure which
has been developed for excising and removing stenotic material from
the vascular system. DCA procedures employ a variety of special
catheters having tissue cutting members (cutters) located at the
distal end of the catheter. In use, the catheter is inserted into a
biological conduit so that the cutter housing is placed adjacent to
the stenotic region with the housing window aligned to the stenotic
material. Stenotic material is invaginated into an opening in the
cutter housing by inflating a balloon opposed to the housing
window. Simultaneous rotation and translation of the cutter sever
the stenotic material which is retained in the nosecone at the
distal end of the catheter. Examples of such devices can be found
in U.S. Pat. Nos. 5,312,425; 5,250,959; 5,181,920; 5,071,425;
4,979,951; 4,781,186; and 4,669,469 (reissued as No. Re. 33,569),
herein incorporated by reference in their entirety. Ablative
methods such as the application of laser energy to the atheroma or
high speed abrasive burrs are also used to widen the blood vessel
at the point of stenosis. Another method of treatment of cardiac
insufficiency employs stents, (mechanical supports). Stents are
placed at the site of the stenosis and expanded to widen the blood
vessel. The stent remains in place as an arterial implant. All of
these techniques are used to open blocked areas of blood vessels in
an attempt to restore the original lumen diameter or provide an
alterative path for blood flow. Although these methods of treatment
are distinct different methods, they share one common problem,
restenosis. A certain percentage of the treated blood vessels will
reocclude (restenose) after a period of time. Restenosis can occur
in as many as 30-40% of the cases. In such restenotic instances,
the original procedure may be repeated or an alternative method for
achieving blood flow may be tried. The common factor in all of
these treatment methods is that they all traumatize the blood
vessel to some extent. There are several reasons why restenosis can
occur. One is that small clots form on the arterial wall. Tears in
the wall expose blood to foreign material and proteins, such as
collagen, which are highly thrombogenic. Resulting clots can grow
gradually, or can contain growth hormones which are released by
platelet within the clot. Additionally, growth hormones released by
other cells, such as macrophages, can cause smooth muscle cells and
fibroblasts in the region to multiply. Further, there is often
complete loss of the normal single layer of cells constituting the
endothelial lining following angioplasty. This layer normally
covers the internal surface of all vessels, rendering that surface
compatible, i.e., non-thrombogenic and non-reactive with blood.
Mechanically, when as angioplasty balloon is inflated, the
endothelial cells are torn away. Prior art procedures also produce
injuries in the arterial wall which become associated with
inflammation. Any kind of inflammatory response may cause the
growth of new tissue. In order to address such problems, the
cardiology community needs to administer drugs which are
biocompatible and in such concentration that they do not induce a
toxic reaction.
Some drugs might have a beneficial effect upon inhibition of the
stenotic growth or even remove the stenotic material but, treatment
of the site of vessel blockage via systemic administration of drugs
has not been successful. The area in need of treatment is very
small relative to the area of the vascular system. Blood flow at
the stenotic region is low and variable. Localized application of
some drugs could achieve the most effective result without
burdening the entire system with large amounts of a drug. One
attempt to localize drug delivery during an angioplasty procedure
is described in U.S. Pat. No. 5,199,951. This patent is limited in
the area of treatment, and method of application. There does not
exist an efficient means for the localized delivery of medicaments
in a biological conduit such as a blood vessel.
What is needed is a method of applying a medicant to a specific
site in a biological conduit to either remove or destroy the
stenotic material or to treat the site of vascular intervention to
prevent restenosis.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a device and method
for applying medicaments to a biological conduit.
In accordance with the above object and those that will be
mentioned and will be apparent below, a device for applying
medicaments to a biological conduit is provided comprising:
a rotatable and axially translatable applicator that is further
comprised of
an outer surface;
a distal end;
an interior reservoir;
a drug contained in said reservoir;
at least one delivery path connecting the interior reservoir to the
surface of the said applicator; and
a drive cable attached to the proximal end of said applicator for
imparting rotational and translational motion to said
applicator,
whereby the medicament contained in said reservoir is delivered
said biological conduit when the applicator is rotated.
In the event that a drug is applied that is effective for removing
or otherwise controlling the stenotic material without need of
excising or compressing stenotic material, the housing window can
be optimized to the extent required to maintain structural rigidity
and permit the largest area of application.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the objects and advantages of the
present invention, reference should be had to the following
detailed description, taken in conjunction with the accompanying
drawing, in which like parts are given like reference numerals and
wherein:
FIG. 1 is a side view of an cutting applicator in accordance with
the present invention.
FIG. 2 is an end view and the applicator of FIG. 2.
FIG. 3 is a side view of a non-cutting embodiment of the present
invention.
FIG. 4 is an end view of the applicator of FIG. 3.
FIG. 5 is another embodiment of a cutting applicator in accordance
with the present invention.
FIG. 6 is an end view and the applicator of FIG. 5.
FIG. 7 is a non-cutting embodiment of the applicator in accordance
with the present invention.
FIG. 8 is an end view and the applicator of FIG. 7.
FIG. 9 illustrates the entry of a device constructed in accordance
with the invention into a blood vessel.
FIG. 10 illustrates the positioning of a device constructed in
accordance with the invention within a blood vessel in conjunction
with an atherectomy catheter.
DETAILED DESCRIPTION OF THE INVENTION
With respect to FIG. 1 is shown a medicament applicator 1 having a
proximal end 5, a distal end 6, a medicament reservoir 20, delivery
paths 31), openings to the exterior 31, a sealing plug 40 and a
cutting edge 50. The applicator 1 is attached to a drive cable 10
at proximal end 5 which is attached to a motor drive (not shown).
Reservoir 20 contains a porous absorbent material 23, such as
cotton, open celled cellulosic foam, open celled polyurethane foam
or the like. The drug to be delivered can be loaded through port 41
into reservoir 20 and absorbed by absorbent material 23 when the
device is manufactured and sealed in place by plug 40 or injected
by means of a hypodermic syringe and needle into reservoir 20
through plug 40 just prior to use. Drugs that have sufficient
storage stability may lend themselves to the preloading approach.
Drugs that have a limited lifetime can be prepared just prior to
the treatment and injected into the reservoir 20 through sealing
plug 40. In a preferred embodiment, the reservoir 20 contains an
absorbent material 23 that will retain the absorbed drug by
absorption until the applicator 1 is rotated above a threshold high
speeds. Thus, the cutting applicator 1 is first rotated and
translated axially to remove the stenotic material. Then, when the
application of drug is desired, the cutting applicator 1 is rotated
an a higher speed that is sufficient to express out the drag of
reservoir 20 via path 30 to opening 31. In this manner, several
cuts may be made in various positions, and drug may be applied to
each cut after it is made. In the embodiment shown in FIG. 1, the
drug delivery paths 30, are at an angle to the perpendicular of the
axis of rotation of the applicator 1 and permit treatment a larger
area of blood vessel that would be possible if the openings were
perpendicular from the axis of rotation and equidistant from a
central point. In this manner, one of ordinary skill in the art can
construct applicators that apply drugs to larger or smaller areas
by changing the placement and number of openings. For example,
therapeutic drugs for treating an injured or diseased area in a
vessel and for combination with the disclosed applicator can
include antiplatelets, antithrombins, and antiproliferatives.
Examples of antiplatelets and antithrombins include sodium heparin,
LMW heparin, hirudin, hirulog, argatroban, forskolin, vapirprost,
prostacyclin, dextran, D-phe-pro-arg-chloromethylketone (synthetic
antithrombin), dipyridamole, glycoprotein IIB/IIIa platelet
membrane receptor antibody, recombinant hirudin, thrombin inhibitor
(from Biogen) and 7E-3B (antiplatelet drug form Centocor). Examples
of antiproliferatives include angiopeptin (somatostatin analogue
from a French company: Ibsen), angiotensin convening enzyme
inhibitors (Captopril (Squibb), Cilazapril (Hoffman-LaRoche) and
Lisinopril (Merk)), calcium channel blockers (Nifedipine),
colchicine, fibroblast growth factor (FGF) antagonists, fish oil
(omega 3-fatty acid), low molecular weight heparin (Wyeth,
Glycomed), histamine antagonists, lovastatin (inhibitor of HMG-CoA
reductase, cholesterol lowering drug from Merk), methotrexate,
monoclonal antibodies (to PDGF receptors, etc.), nitroprusside,
phosphodiesterase inhibitors, prostacyclin analogues, prostaglandin
inhibitor (Glaxo), seramin (PDGF antagonist(, serotonin blockers,
steroids, thioprotease inhibitors, triazolopyrimidine (PDGF
antagonist from Japanese company). While the foregoing therapeutic
agents have been used to prevent or treat restenosis and
thrombosis, they are provided by way of example and not meant to be
limiting, as other therapeutic drags may be developed which are
equally applicable for use with the present invention.
FIG. 9 illustrates the entry of a device constructed in accordance
with the invention into a biological conduit, showing a catheter 62
containing a device in accordance with the invention being inserted
into a blood vessel 64 through an incision 66.
With reference to FIG. 10, a device 70 constructed in accordance
with the invention is positioned within a blood vessel 64.
Applicator 72 attached to cable 74 is disposed within the housing
68 of a catheter 76.
FIG. 2 shows the relative positions of the drug delivery paths 30
with respect to a plane perpendicular to the central axis of the
cutting applicator 1.
FIG. 3 describes an embodiment wherein applicator 1 does not
perform any cutting action. With respect to FIG. 3 is shown a
medicament applicator 1 having a proximal end 5, a distal end 6, a
medicament reservoir 20, delivery paths 30, exterior openings 31,
and sealing plug 40. Applicator 1 is attached to drive cable 10
which is attached to a motor drive (not shown). As in the previous
embodiment, the drug to be delivered can be loaded into reservoir
20 through port 41 and sealed in place by plug 40. In this
preferred embodiment, reservoir 20 contains an absorbent material
that will retain the absorbed drug until applicator 1 is rotated at
speed high enough to overcome the absorptive forces. Once
applicator 1 is positioned, drug is released when it is rotated at
a suitable speed.
FIG. 4 shows the relative positions of the drug delivery paths 30
with respect to a plane perpendicular to the central axis of the
cutting applicator 1.
FIG. 5 shows an embodiment of applicator 1 wherein the drug
reservoir is devoid of any absorbent material and escape of the
drug is controlled by the diameter of the capillary-like drag
delivery paths 32 and the speed of applicator 1. The term
"capillary-like" is used herein to describe the ordinary attraction
between liquids and solids wherein a capillary bore will
spontaneously fill when contacted with liquid and will not empty
under ordinary gravitational forces. In the particular embodiment,
the drug delivery paths 32 are slits of capillary dimensions. Slits
32 communicate with the surface via surface openings 33 and are
wide enough to apply drug to a broader area than when a bore and a
hole of capillary dimensions are used. As in the previous
embodiment, the drug to be delivered can be loaded into the
reservoir 22 when the device is manufactured through port 41 and
sealed in place by plug 40 or alternatively, prepared just prior to
treatment and injected into reservoir 31 through sealing plug 40 by
means of a hypodermic syringe and needle. FIG. 6 shows the
capillary nature of slits 33 more clearly. One skilled in the art
can construct differently sized capillary conduits for the delivery
of distinct amounts of drug at a desired rotational speed.
FIG. 7 describes another embodiment wherein the applicator 1 does
not perform any cutting action. With respect to FIG. 6 is shown a
medicament applicator 1 having proximal end 5, distal end 6,
medicament reservoir 22, delivery paths 32, exterior openings 33,
and sealing plug 40. Applicator 1 is attached to drive cable 10 at
proximal end 5 which is attached to a motor drive (not shown). The
drug to be delivered can be loaded into reservoir 22 through port
41 and sealed in place by plug 40. Drug reservoir 22 is devoid of
any absorbent material and delivery of the drug is controlled by
the diameter of the capillary-like drug delivery path 32 and the
speed of rotation of applicator 1. In this specific embodiment,
drug delivery paths 32 are slits of capillary dimensions. Delivery
paths 32 communicate with the surface of applicator 1 via surface
openings 33 and are wide enough to apply drug to a broader area
than would be possible if a single bore and hole of capillary
dimensions were used.
The foregoing detailed descriptions have described preferred
embodiments of the drug delivery applicator of the instant
invention and are to be understood to be illustrative only and not
limiting of the disclosed invention. Particularly, the specific
details of the drug delivery path and the construction of the
reservoir can be varied to obtain different delivery rates and area
of coverage and still be within the scope of the disclosed
invention. Thus, the invention is to be limited only by the claims
set forth below.
* * * * *